Fatal error on database migration with Trac v1.0.1

[ryank-inovonics]

When attempting to migrate a Trac v1.0.1 site from SQLite to PostgreSQL, got this error:

Copying tables:
ProgrammingError: Cannot operate on a closed database.
Exception AssertionError: AssertionError() in <bound method PooledConnection.__del__ of <trac.db.pool.PooledConnection object at 0x95ef324>> ignored
    attachment table...

After poking around in admin.py found that creating the new environment closes any existing database connections, namely the one for the old environment's SQLite database. Swapped the new environment creation section with old environment's database open and query. With this change the migration completed successfully. See attached diff for the changes made to admin.py.

Maybe a change in behavior of environment creation in Trac 1.0.x?

[Jun Omae]

Thanks for the patch. Looks harmless. But I cannot reproduce it with Python 2.5/2.6/2.7 while migrating SQLite to PostgreSQL. Could you please provide the details of your environment?

[ryank-inovonics]

Environment details:

• Ubuntu 12.04
• Python 2.7.3
• Trac 1.0.1
• PostgreSQL 9.1.9
• SQLite 3.7.9 & SQLite 2.8.17

Using a Python virtualenv with these packages installed (pip list):

AdvancedTicketWorkflowPlugin (0.11dev-r9962)
argparse (1.2.1)
BlackMagicTicketTweaks (0.11r1)
distribute (0.6.38)
docutils (0.10)
flup (1.0.3.dev-20110405)
Genshi (0.7)
NavAdd (0.1.1)
PlantUML (2.0dev-r12389)
psycopg2 (2.5)
Pygments (1.6)
pytz (2013b)
Trac (1.0.1)
TracAccountManager (0.4.3)
TracCustomFieldAdmin (0.2.8-r12166)
TracIniAdminPanel (1.0.1-r13010)
TracMasterTickets (3.0.5dev-r12950)
TracMigratePlugin (0.12.0.1)
TracPermRedirect (3.0)
TracWysiwyg (0.12.0.4-r12680)
wsgiref (0.1.2)

Maybe one of the Trac plugins I have installed has a side-effect of closing the open database connections on environment create?

[Jun Omae]

In 13348:

tracmigrate: makes migration more robust by retrieving connection after upgrade of new environment (closes #11246)

Patch by ryank-inovonics.

[Jun Omae]

Thanks for your providing the details. Reproduced with only Trac 1.0.1, MasterTicketsPlugin and TracMigratePlugin 0.12.0.1.

Great Catching! Many thanks!